The Surgery Core (Core B) will continue to strengthen the overall program by serving as a central facility performing mouse kidney transplants for each of the three projects of the program. This resource will allow concentration of microsurgical expertise and effort, standardization of surgical approaches, minimize surgically imposed disparities in the grafts, and care for graft recipients in all three projects, and more concerted effort to be expended on the design and performance of experiments within each project of the program. The specific tasks of Core B will be to: a) To provide renal transplants and when necessary native kidney nephrectomies for investigators in the individual projects of the program; b) to monitor the health of the renal transplant recipients and test for evidence of renal dysfunction; and, c) to assist investigators with the experimental treatments proposed in the projects of the program.